Conventionally, an image forming apparatus such as an MFP includes a scanner unit and a printer unit. The scanner unit reads a document, and image data read by the scanner unit is processed so as to be printed by the printer unit.
In addition, the image forming apparatus is provided with an automatic document feeder (ADF), and the scanner unit reads the document transported by the ADF or a document placed on a platen. Moreover, the ADF transports the document so that both sides of the document can be read.
When both sides of the document are read, the document loaded on a document tray is fed to the scanner unit from the uppermost page of the document in order, and the front side of the document is read. Thereafter, the document is switched back so as to be reversed, and the back side of the document is read. After the back side is read, the document is idly reversed by means of a reversing mechanism and discharged from a paper discharge port, whereby the document is discharged to a paper discharge tray with the front side down in the same page order as before the document is fed.
In conventional automatic document feeders, when both sides of the document are read, the document needs to be switched back so as to be reversed, or the idle reverse needs to be performed when the document is discharged. Accordingly, there is a problem of a decrease in productivity.